Package org.apache.lucene.search.knn

Class MultiLeafTopKnnCollector

java.lang.Object

org.apache.lucene.search.AbstractKnnCollector

org.apache.lucene.search.TopKnnCollector

org.apache.lucene.search.knn.MultiLeafTopKnnCollector

All Implemented Interfaces:

KnnCollector

public final class MultiLeafTopKnnCollector
extends TopKnnCollector

MultiLeafTopKnnCollector is a specific KnnCollector that can exchange the top collected results across segments through a shared global queue.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields inherited from class org.apache.lucene.search.TopKnnCollector

queue

Fields inherited from class org.apache.lucene.search.AbstractKnnCollector

visitedCount

Constructor Summary

Constructors

Constructor	Description
MultiLeafTopKnnCollector(int k, int visitLimit, BlockingFloatHeap globalSimilarityQueue)

Method Summary

Modifier and Type	Method	Description
boolean	collect(int docId, float similarity)	Collect the provided docId and include in the result set.
float	minCompetitiveSimilarity()	This method is utilized during search to ensure only competitive results are explored.
TopDocs	topDocs()	This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending.
String	toString()

Methods inherited from class org.apache.lucene.search.AbstractKnnCollector

earlyTerminated, incVisitedCount, k, visitedCount, visitLimit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

MultiLeafTopKnnCollector

public MultiLeafTopKnnCollector(int k,
                                int visitLimit,
                                BlockingFloatHeap globalSimilarityQueue)

Parameters:

k - the number of neighbors to collect

visitLimit - how many vector nodes the results are allowed to visit

Method Detail

collect

public boolean collect(int docId,
                       float similarity)

Description copied from interface: KnnCollector

Collect the provided docId and include in the result set.

Specified by:

collect in interface KnnCollector

Overrides:

collect in class TopKnnCollector

Parameters:

docId - of the vector to collect

similarity - its calculated similarity

Returns:

true if the vector is collected

minCompetitiveSimilarity

public float minCompetitiveSimilarity()

Description copied from interface: KnnCollector

This method is utilized during search to ensure only competitive results are explored.

Consequently, if this results collector wants to collect `k` results, this should return Float.NEGATIVE_INFINITY when not full.

When full, the minimum score should be returned.

Specified by:

minCompetitiveSimilarity in interface KnnCollector

Overrides:

minCompetitiveSimilarity in class TopKnnCollector

Returns:

the current minimum competitive similarity in the collection

topDocs

public TopDocs topDocs()

Description copied from interface: KnnCollector

This drains the collected nearest kNN results and returns them in a new TopDocs collection, ordered by score descending. NOTE: This is generally a destructive action and the collector should not be used after topDocs() is called.

Specified by:

topDocs in interface KnnCollector

Overrides:

topDocs in class TopKnnCollector

Returns:

The collected top documents

toString

public String toString()

Overrides:

toString in class TopKnnCollector